Selective gear reduction units



Feb. 24, 1948. c. w. DROUGHT SELECTIVE GEAR REDUCTION UNITS Filed July 12, 1945 2 Sheets-Sheet 1 QQQ R Q g a... w

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Feb. 24, 1948. c. w. DROUGHT 2,436,746

SELECTIVE GEAR REDUCTION UNITS Filed July 12, 1945 2 Sheets-Sheet 2 Patented Feb. 24, 1948 I UNITED STATES PATlZN-T 1 OFFICE I SELECTIVE enilf ucnon lmrrs I CharIeeW. Drought, Berwyn, 111.

Application July 12, 1948, Serial No. 494.293 6 Claims. (01. 74-325) The present invention relates to gear drives, such as used on overhead trolley cranes, and particularly on the bridge thereof spanning the bay, for driving the wheels on the rails at the sides of the bay and at the ends of the bridge, and

.has reference more particularly to the gear reduction unit selectively bodily connected in the gear train between the driving motor and the wheel shaft.

When designing a drive for an overhead trolley crane it has been customary to build in the gear reduction drive between the motor and-the shaft of the traction wheels on the tracks at the side of the bay. The particular speed of travel of the bridge for the motor used may not be what is desired for the loads the crane is intended to carry. To them redesign the gear ratio at the time of installation would involve loss of time and additional cost.

An object of the present invention is to provide a novel gear unit which is readily installed as a unit in operative connection with the driving gear or pinion on the motor shaft "and the driven gear on the wheel shaft, and setting the unit in adjusted or selective position for the proper meshing of the gears of the unit with the 7 bridge adjacent to the housing for the gear train.

Accordingly, when a crane is designed and built it will have a gear unit in place. When the installation is made, and it is found that a different gear ratio is necessary for the particular work the crane is to perform, it is simply necessary to remove the gear unit first put in the device and to replace it by a gear unit having the desired gear ratio. In doing so the unit isadjustably secured in place to the housing and with ,a gearin mesh with the gear or pinion on the motor shaft and another gear in mesh with the 'driven gear on the wheel shaft. By way of example it may be assumed that when the crane is built the ratio of the driving motor gear to the driven gear of the unit is 1:2 and that the ratio of the driving gear of the unit to the driven gear on the wheel shaft is 2:3, then the overall ratio of the drive 18123. but that'might be a too fast driving of the wheel shaft. so the new unit set in place may be such that the ratios would be 1:3 and 1:2 with the overall ratio of 1:6 whereby the wheel shaft rotates one-half as fast as before. On the other hand, if it be desired to travel the bridge faster, then, a gear unit may be chosen and connected whereby the ratios would be 2:3 and 3:4 with the overall ratio of 1:2 whereby the wheel shaft rotates two-thirds as fast as the first example given above.

Another object of the invention is to provide a novel structure wherein the wheel shaft gear may be located in alternative positions to be driven by the gear unit depending upon the position of the larger gear in the unit, and also whereby the wheel shaft gear may be moved to a position to permit passage of the larger gear of the unit when such larger gear is in operative relation with the motor gear behind the smaller gear of the unit.

Other objects, advantages, capabilities, features and the like are comprehended byQthe invention as will later appear and as are inherently possessed by the invention.

Referring to the drawings:

Fig. 1 is a front view in elevation of an embodiment of the invention;

Fig. 2 is a longitudinal sectional view taken in a plane represent( 1 by line 2-2 in Fig. 1 of the drawings;

Fig. 2a is a fragmentary sectionalview of a detail of thedevice;

Fig. 3 is a fragmentary sectional view similar to that shown on Fig. 2 but showing the relationship of a unitwith a difierent ratio of gears;

Fig. i is a fragmentary sectional view of an alternative form of device;

Fig. 5 is a fragmentary vertical sectional view of a further alternative form of device; and

Figs. 6 and 7 are fragmentary front elevational views of the device shown in Fig. 5 and showing the use of different ratioed gears in the unit.

Referring more in detail to the drawings the embodiments chosen to illustrate the invention are shown as comprising a housing 5 located upon and suitably fixed to a platform 2 of a bridge of the crane. The housingi has a rear wall 3, a surrounding wall 4 which is curved atsthe top and extends down at the sides to a base 5, and a front wall 6. The surrounding wall 6 has a frontal flange I provided with a series of holes for the receiving of bolts or screws or similar securing elements 8 for fastening the front wall 6 in place, the margin of the wall 6 also having corresponding holes, as holes 3, for the passage of the securing elements 5.

On the platform 2 is an electric motor Ill having a shaft ll extending through an opening i2 provided in the rear wall 3 and into the chamber l3 of the housing To the free end of the shaft II is fastened a driving gear or pinion l4 backed by a collar I5 on the shaft ii and abutting a shouldered part of the shaft II. In the opening I2 is located a suitable sealing means I 5 about the shaft I I.

At the upper part or the housing I the rear and front walls 3 and 5 are provided with alined holes I1 and I8 respectively for receiving and holding bearing boxes I5 and 20. These bearing boxes have flanges 2| and 22 having a series of suitable holes in registry with like holes in the walls 3 and 5 for the reception of securing elements to fasten the boxes I9 and 25 firmly to the walls 3 and 5. The boxes I9 and 25 have hubs 23 and 24 extending through and fitting in the holes l1 and I8 and carrying bearing means 25 and 25, which may be of the ball bearing type, for rotatably supporting a shaft segment 21 connected, as keyed or splined, to a driven gear- 25. Between the gear 23 and the bearing means 25 and 25, and on the shaft 21, are spacer sleeves 23 and 35 abutting the ear 25 at the inner ends or the sleeves and bearing means 25 and 25 at the outer ends of the sleeves. Suitable abutting rings 3| and 32 are provided at the inner ends of the hubs 23 and 24 and around the spacers 29 and 35. The spacers 23 and 30 maybe interchanged in place so that the gear 25 may occupy a locus to the right of that shown in Fig. 2 when intended to be driven at different speeds as explained below.

The shaft portion 21 is a segment of a long shaft connected to the wheels of the bridge of the crane and is connected at its ends by suitable couplings 33 and 34 which are located within the bearing boxes I3 and 25 and which may act as thrust elements with reference to the bearing elements 25 and 25. The shaft portion 21 continues with shaft segments 35 and 35 which extend to the wheels running on the rails at the side of the bay. The couplings 33 and 34 afford a facile .n'leans for disconnecting the shaft segment 21 from the shaft segments 35 and 35 when it is desired to interchange the spacer sleeves 29 and 35, as shown for example in Fig.4. The outer ends of the boxes I9 and 25 are sealed off from the outside by suitable seals 31 and 35 provided in the hub portions 39 and 45 of the boxes I! and 25.

The front wall 5 towards its lower portion is provided with an opening 4| which is preferably of rectangular shape and has its vertical side edge portions or margins 42 and 43 provided with a series of holes 44 and 45 for the reception of securing elements such as screws or bolts or the like 45. See Fig. 2a. In overlapped relation with said side portions 42 and 43 are vertical side bars such as Z-bars 41 and 43, the base flanges 49 and 55 of which have openings for the passage or the securing elements 45 which rigidly hold the flanges with the vertical portions 42 and 43. The other or outer flanges 5| and 52 of the Z-bars are spaced from the edge portions ormargins 42 and 43 to provide vertical channels 53 and 54 therebetween for affording vertical adjustment of the plate 55 as hereinafter described. This plate 55 is preferably rectangular in shape and sufficiently long to close the opening 4| in. all vertical positions of the plate when adjusted as hereinafter explained. Each of the vertical side edge portions or margins of the plate 55 is provided with one or more vertically spaced holes for the reception of securing elements such as screws 55 (see Fig. 2a) and the marginal or edge portions 42 and 43 are provided with vertical series of threaded holes or sockets 51 for receiving the threaded ends of the screws 55 when the plate 5| has been adjusted in vertical position to desired height.

The plate 55 is a rigid part of a bearing box 55 7 having an end cap 53 and including bearing units 55 and 5| which may be of the ball bearing type as shownjfor rotatably supporting a gear shaft 52 carrying gears 53 and 54 keyed or splined to that shaft. The bearing units 50 and 5| are held in spaced relation by a spacer 55 between them and on the shaft 52, a thrust element 55 as a nut screwed on the threaded end 51 or the shaft 52, and a thrust collar 55 on the shaft 52 and between the bearing means 50 and the gear 53, The inner end 59 of the shaft 52 is threaded and has a nut 15 for clamping the gears 53 and 54 together and for holding them in place. The gears 53 and 54 are in the chamber I3 with the gear 53 in mesh with the gear 23 and the gear 54 in mesh with the gear I4, as shown in Fig. 2. It willbe noted that in Fig. 2 the gear 54 is of smaller diameter than the gear 53 but these gears may be of a different diameter ratio, such as shown in Fig. 3

, wherein the gears 1| and 12 are of the same or substantially the same diameter whereby the drive efiected is the same as if gear I4 were in mesh with the gear 25.

In both cases the gear unit is inserted or withdrawn through the opening 4 I To do so the side clamping z-bars 41 and 48 are removed. When removing a gear unit, the screws 55 are also removed and then the unit slid out axially of the shaft 52. When replacing a gear unit with a set of gears with a dlflerent ratio the nut 10 is removed and also the gears 54 and 53 and another set put in place such as gears 1| and 12, and the nut 15 screwed back in place. The unit is then slid in place to mesh gear 1| with gear I4 and gear 12 with gear 28. The axis of the shaft 52 and hence of the unit will be higher than that shown in Fig. 2 and the plate 55 is thus secured in place in a higher position over the opening 4| by screwing in the screws 55 in the higher holes or sockets 51 provided in the vertical side edge portions 42 of the wall 5. Then the side Z-bars are secured in place by way of the bolts or screws 45 and with the flanges 5| overlapping the side edge portions of the adjustable plate 55 and clamping it tight with the side portions 42of the wall 5, besides also preventing the screws 55 working loose or working out.

Fig. 4 shows a drive wherein only one intervening gear 13 is used in the unit. In this case the spacers 29 and 35 on the wheel shaft are inter changed in position on the shaft segment 21 and the gear 28 positioned in the plane of the motor gear I4 with the gear 13 meshed with both the gears I4 and 25, To make up for the gear 53 not included a thrust bushing 14 is provided on the shaft 52 between the gear 13 and the bearing 55 in lieu of the bushing ring 58 shown in Fig. 2. In other respects the gear 13 forms part of a unit with the bearing housing 58 as in the cases shown in Figs. 2 and 3.

In the alternative structure shown in Figs, 5, 6 and 7 the gear unit instead of meshing axially with the gears I4 and 25 is made to swing in an are about the axis of the motor shaft II or gear I4. This is convenient when-using a gear which meshes with the motor gear i4 of greater diameter than the gear which meshes with the gear assen The movable gear unit comprises gears 15 and 15 connected to the shaft 60 and held in place by the nut screwed onto the threaded end 69 gear l4 and constituting the rear gear being of greater diameter than the gear 18 constituting the front gear and which meshes with gear 28.-

A thrust ring 68 on the shaft 62 is interposed between the gear 16 and the bearing unit 60' (see F'g. 2 for this part) in the bearing housing 58. The front wall 6 of the housing I has an areshaped opening 11 (see Figs. 6 and) in which extends an inner hubbed end of a bearing box or housing 58 and along which the hubbed end may be moved to bring the gear 16 into mesh with the gear, 28 or out of mesh therewith. The bearing box or housing 58 has a plate 55a which is preferably arc shaped and of such size designed and adapted to cover the arc slot H in any and all positions of the gear unit, in the same way as plate 55 in Figs. 1 and 2 covers the rec,- tangular opening in the'wali 6. Are shaped 2- bars lii'may be attached to the wall 6 in the same way as the Z-bars 41 and 48 in Figs. 1 and 2 and have suitable holes for the securement of screws or bolts (not shown) for holding the unit in adjusted position, also similar to that in Figs. 1 and 2.

Figs, 6 and 7 differ only in that in Fig. 7 the gear 19, corresponding to the gear 16 in Fig. 6, is larger. Any other size of gear may be used as desired and necessary to obtain the final rotary speed of the wheel shaft 21. When it is desired to change gears of different sizes, such as gears 16 and 19, the nut 10 on shaft end 69 i loosened and removed. This is possible by use of a wrench, such as a socket wrench, through an opening 80 provided in the rear wall 3 of the main housing or casing I, The gears 16 and or 19 and 15 may be removed through the rear opening 80 and a new set inserted in place and the nut 10 secured on the threaded end of the shaft. The opening 80 is normally closed by a plate 8! held secured to the rear wall 3 of the housing I by any' suitable securing means such as screws, bolts or the like.

While I have herein described and upon the drawings shown a few illustrative embodiments of the invention, it is to be understood that the invention is not limited thereto but comprehends other constructions, details, arrangements of parts, features, and the like, without departing from the spirit of the invention.

I claim:

1. A gear drive of the reduction type of the character described, comprising a base, a motor on the base and having a shaft, a driven shaft, a gear housing fixed to the base in line with the motor and having bearing means for rotatably supporting the driven shaft, said housing having spaced forward and rear walls provided with alined openings through which the driven shaft extends, a driven gear secured to the driven shaft within said housing, said housing being provided with an opening in the rear wall thereof oppo site the motor for the extension therethrough of the motor shaft, a driving gear on the motor of the shaft 62, the gear 15 which meshes with shaft within said housing, an intermediate gear unit operativeiy connected to said driven andsaid driving gears withinsaid'housing, the for- 6 ward wall of said housing being provided with an opening aiined with said gear unit, a cover memberfor said forward ,wall opening, an ,out-

board bearing unit'carried by said cover memher, a shaft Joumalled in said outboard bearing as the sole support therefor and projecting into said housing for rotatively carrying said inter mediate gear unit. and said cover member being adjustable to change the position of said outboard bearing unit and the shaft transversely of said opening for the accommodation of gear unit of various'speed ratios upon said shaft and in operative driving connection with said driving a and driven gears.

2. A gea'r drive of the reduction type of the character described, comprising a base, a motor on the base and having a shaft, a driven shaft, a gear housing fixed to the base in line with the motor and having bearing means .for rotatably sup orting the driven shaft, said housing having opening means through which the driven shaft extends, a driven gear secured to the driven shaft within said housing, said housing being provided with an opening in the rear wall thereof opp site the motor for the extension therethrough of the motor shaft, a driving gear on the motor shaft within said housing, an intermediate gear unit operatively connected to said driven and 'said driving gears within said housing, the forward wall of said housing being provided with an opening alined with said gear unit, an outboard bearing unit disposed in registry with said front wall opening, an intermediate shaft journailed in said bearing unit as the sole support therefor and projecting into said housing as a journalled support for said intermediate gear unit, and adjustable mounting means for supporting said outboard bearing unit and hence said intermediate shaft in selected positions transversely of said opening for the alternative accommodation of gear unit arrangements of different speed ratio on said intermediate shaft.

3. A gear drive of the reduction type of the character described, comprising a base, a motor on the base andhaving a shaft. a driven shaft, a gear housing fixed to the base in line with the motor and having bearing means for rotatably supporting the driven shaft, said housing having spaced forward and rear walls of which at least one is provided with opening means through which the driven shaft extends, a driven gear secured to the driven shaft within said housing, said housing being provided with an opening in the rear wall thereof opposite the motor for the extension therethrough of the motor shaft, a driving gear on the motor shaft within said housing, an intermediate gear unit having gears ing casing for said latter bearing means, a plate extending radially from said bearing casing and being of a larger size than the opening in said forward wall of the housing, and means for securing said plate to said forward wall and to close said latter opening.

4. A gear drive of the reduction type of the "character described, comprising a base, a motor 7 on the base and having a shaft, a driven shaft, a gear housing fixed to the base in line with the motor and having bearing mean for rotatably supporting the driven shaft, said housing having spaced forward and rear walls provided with alined openings through which the driven shaft extends, a driven gear secured to the driven shaft within said housing. said housing being provided with an opening in the rear wall thereof opposite the motor for the extension therethrough of the motor shaft, 9. driving gear on the motor shaft within said housing, an intermediate gear unit having gears of a given ratio within said housing and operatively connected to said driving and driven gears, the forward wall of said housing being provided with an opening alined with said gears of said intermediate gear unit and being of a diameter sufficient for the axial passing therethrough of 'the larger gear of said gears of said intermediate gear unit, said gear unit having a shaft extending through said latter opening, bearing means for said gear unit shaft, a bearing casing for said latter bearing means, a plate extending radially from said hearing casing and being of a larger size than the opening in said forward wall of the housing, and means for securing said plate to said forward wall and to close said latter opening, said bearing means for said gear unit shaft having axially spaced bearing units, a spacer on said latter shaft and between said spaced bearing units to abut said spaced bearing units, an abutting member secured to the forward portion of said shaft in abutting relation to the forward side of the forward bearing unit of said bearing units, and another abutting member on said shaft between said other of said bearing units and the forward gear of said gears of said intermediate gear unit.

5. A gear drive of the reduction type of the character described, comprising a base, a motor on the base and having a shaft. a drivenshaft, a gear housing fixed to the base in line with the motor and having bearing means for rotatahly supporting the driven shaft, said housing having spaced forward and rear walls provided with alined openings through which the ;driven shaft extends, a driven gear secured to the driven shaft within said housing, said housing being provided with an opening in the rear wall thereof opposite the motor for the extension therethrough of themotor shaft, a driving gear on the motor shaft within said housing, an intermediate gear unit operatively connected to said driven and said driving gears within said housing, the forward wall of said housing being provided with an opening alined with said gear unit, said gear unit having a shaft extending through said latter opening, bearing means for said gear unit shaft, said latter opening being of arc shape having its center of curvature in the axis of said driving gear, a. bearing casing forsaid latter I bearing means and having a rearwardiy extending hub fitting slidably'ln said are shaped opening, and means for securing said bearing casing to said forward wall of said housing and in position for the gear unit to mesh with said driven scar on said driven shaft.

6, A gear drive of the reduction type of the character described, comprising a base, a motor on the base and having a shaft, a driven shaft, 9. gear housing fixed to the base in line with the motor and having bearing means for rotatabiy supporting the driven shaft, said housing having spaced forward and rear walls provided with alined openings through which the driven shaft extends, a driven gear secured to the driven shaft within said housing, said housing being provided with an opening in the rear wall thereof opposite the motor for the extension therethrough of the motor shaft, a driving gear on the motor shaft within said housing, an intermediate gear unit operatively connected to said driven and said driving gear within said housing, the forward wall of said housing being provided with an opening alined with said gear unit, said gear unit having a shaft extending through said latter opening, bearing means for said gear unit shaft, said latter opening being of are shape having its center of curvature in the axis of said driving gear, a bearing casing for said latter bearing means and having a rearwardly extending hub fitting slidably in said are shaped opening, and means for securing said bearing casing to said forward wall of said housing and in position for the gear unit to mesh with said driven gear on said driven shaft, said securing means comprising a plate extending laterally from said hearing casing and being of a larger size than said are shaped opening for closing said are shaped opening in all positions of said gear unit and bearing housing about the axis of said driving gear, and said plate and forward wall also in-- cluding securing elements for selectively securing said plate to said forward wall in any selected fxfiition of said gear unit and said bearing hous- CHARLES W. DROUGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

